Structural Control of Surface Modified Layrs through Ultrasonically Distributed Electrical Discharges.

通过超声波分布式放电对表面改性层进行结构控制。

基本信息

批准号：
07555531
负责人：
TSUNEKAWA Yoshiki
金额：
$ 0.58万
依托单位：
Toyota Technological Institute
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555531/
关键词：
In-situ Composite Layr Ultrasonic Vibration Electrical Discharge Alloying Surface Modification Aluminum Alloy Substrate Titanium-carbide Precipitate Compositional Gradient Surface Roughness TiAlマトリックス TiC TiAl生成複合材料アルミニウム合金表面改質 /

项目摘要

In order to improve friction and wear characteristics, surface modification of aluminum matrix composites was carried out by applying the new method named Electrical Discharge Alloying, in which each electrical discharge is forcibly scattered by ultrasonic vibration. Titanium contained in the green compact eletrode, and also carbon and silicon decomposed from the working fluid are transferred to the substrate surface through a single discharged arc. Sinece the application of ultrasonic vibration to the aluminum alloy substrate makes the amount of transferred elements increase, the thickness of modified layrs remarkably become thicker. Then, the volume fraction of in situ TiC in the modified surface increases with applying ultrasonic vibration, so that the hardness of modified surfaces becomes high. The process, electrical discharge alloying, makes it possible not only to coat a composite layr containing in situ TiC with a thickness of nearly 80 mum within a few minutes, but also to get high volume fractions of TiC by applying ultrasonic vibration, which is an additional process parameter to discharge conditions. Hradness of the modified surfaces can be controlled to have any value of 4-14 GPa by varying the volume fraction of TiC.It is also recognized that the process improves wear resistance of the modified surfaces.

为了改善摩擦和磨损特性，采用放电合金化新方法对铝基复合材料进行表面改性，其中每次放电均通过超声波振动强制分散。生坯电极中所含的钛以及从工作流体中分解的碳和硅通过单次放电电弧转移到基底表面。由于对铝合金基体施加超声波振动使得转移元素的量增加，因此改性层的厚度显着变厚。然后，随着超声振动的施加，改性表面中原位TiC的体积分数增加，使得改性表面的硬度变高。放电合金化工艺不仅可以在几分钟内原位涂覆厚度近80μm的含TiC的复合层，而且可以通过施加超声波振动获得高体积分数的TiC，这是一种放电条件的附加工艺参数。通过改变TiC的体积分数，可以将改性表面的硬度控制在4-14GPa的任意值。还认识到该工艺提高了改性表面的耐磨性。